xref: /linux/arch/arm64/lib/crc32-glue.c (revision 37b33c68b00089a574ebd0a856a5d554eb3001b7)
1 // SPDX-License-Identifier: GPL-2.0-only
2 
3 #include <linux/crc32.h>
4 #include <linux/linkage.h>
5 #include <linux/module.h>
6 
7 #include <asm/alternative.h>
8 #include <asm/cpufeature.h>
9 #include <asm/neon.h>
10 #include <asm/simd.h>
11 
12 #include <crypto/internal/simd.h>
13 
14 // The minimum input length to consider the 4-way interleaved code path
15 static const size_t min_len = 1024;
16 
17 asmlinkage u32 crc32_le_arm64(u32 crc, unsigned char const *p, size_t len);
18 asmlinkage u32 crc32c_le_arm64(u32 crc, unsigned char const *p, size_t len);
19 asmlinkage u32 crc32_be_arm64(u32 crc, unsigned char const *p, size_t len);
20 
21 asmlinkage u32 crc32_le_arm64_4way(u32 crc, unsigned char const *p, size_t len);
22 asmlinkage u32 crc32c_le_arm64_4way(u32 crc, unsigned char const *p, size_t len);
23 asmlinkage u32 crc32_be_arm64_4way(u32 crc, unsigned char const *p, size_t len);
24 
crc32_le_arch(u32 crc,const u8 * p,size_t len)25 u32 __pure crc32_le_arch(u32 crc, const u8 *p, size_t len)
26 {
27 	if (!alternative_has_cap_likely(ARM64_HAS_CRC32))
28 		return crc32_le_base(crc, p, len);
29 
30 	if (len >= min_len && cpu_have_named_feature(PMULL) && crypto_simd_usable()) {
31 		kernel_neon_begin();
32 		crc = crc32_le_arm64_4way(crc, p, len);
33 		kernel_neon_end();
34 
35 		p += round_down(len, 64);
36 		len %= 64;
37 
38 		if (!len)
39 			return crc;
40 	}
41 
42 	return crc32_le_arm64(crc, p, len);
43 }
44 EXPORT_SYMBOL(crc32_le_arch);
45 
crc32c_le_arch(u32 crc,const u8 * p,size_t len)46 u32 __pure crc32c_le_arch(u32 crc, const u8 *p, size_t len)
47 {
48 	if (!alternative_has_cap_likely(ARM64_HAS_CRC32))
49 		return crc32c_le_base(crc, p, len);
50 
51 	if (len >= min_len && cpu_have_named_feature(PMULL) && crypto_simd_usable()) {
52 		kernel_neon_begin();
53 		crc = crc32c_le_arm64_4way(crc, p, len);
54 		kernel_neon_end();
55 
56 		p += round_down(len, 64);
57 		len %= 64;
58 
59 		if (!len)
60 			return crc;
61 	}
62 
63 	return crc32c_le_arm64(crc, p, len);
64 }
65 EXPORT_SYMBOL(crc32c_le_arch);
66 
crc32_be_arch(u32 crc,const u8 * p,size_t len)67 u32 __pure crc32_be_arch(u32 crc, const u8 *p, size_t len)
68 {
69 	if (!alternative_has_cap_likely(ARM64_HAS_CRC32))
70 		return crc32_be_base(crc, p, len);
71 
72 	if (len >= min_len && cpu_have_named_feature(PMULL) && crypto_simd_usable()) {
73 		kernel_neon_begin();
74 		crc = crc32_be_arm64_4way(crc, p, len);
75 		kernel_neon_end();
76 
77 		p += round_down(len, 64);
78 		len %= 64;
79 
80 		if (!len)
81 			return crc;
82 	}
83 
84 	return crc32_be_arm64(crc, p, len);
85 }
86 EXPORT_SYMBOL(crc32_be_arch);
87 
crc32_optimizations(void)88 u32 crc32_optimizations(void)
89 {
90 	if (alternative_has_cap_likely(ARM64_HAS_CRC32))
91 		return CRC32_LE_OPTIMIZATION |
92 		       CRC32_BE_OPTIMIZATION |
93 		       CRC32C_OPTIMIZATION;
94 	return 0;
95 }
96 EXPORT_SYMBOL(crc32_optimizations);
97 
98 MODULE_LICENSE("GPL");
99 MODULE_DESCRIPTION("arm64-optimized CRC32 functions");
100